Add second language support with root path in an existing ASP.NET WebForms site

Question

I have inherited from a very small ASP.NET WebForms project, and my customer would like to add a second language to it.

For every "somepage.aspx", I'd like to support a "second language path" version of it, like "fr/somepage.aspx". I'd like to handle this using normal globalization (CurrentCulture + resource files in both languages) and avoid having to duplicate each page. I must keep the original paths valid, thus I have excluded ASP.NET MVC for now (for lack of knowing if I could continue to support ".aspx" paths).

Is this possible?

• Rakesh: Hope this will help you: stackoverflow.com/questions/373106/…
• Martin Plante: It does offer a solution for a fresh start, but in my case, I have to keep the existing paths valid. The real question is "how can I make "site.com/page.aspx" handle a request to "site.com/fr/page.aspx" but keeping "site.com/fr/page.aspx" as the URL the user sees.
• Nick Bork: I suppose you could create two Routes (first route for page with language and second for page without language) and create a constraint that matches the languages you want to accept. See msdn.microsoft.com/en-us/magazine/dd347546.aspx and weblogs.asp.net/scottgu/archive/2009/10/13/…. are all of your paths off the root of your site or do you have N number of folders you want to support too?
• Michael Liu: @MartinPlante I tagged this question with "c#" based on your profile. Please change it if you expect another language.
• Martin Plante: @Splash-X You should put that comment as an answer, since it's exactly what I was looking for. Currently, the site is all in the root. I'll simply support routes for "fr/..." and "en/...".

Answer 1

URL Routing is avalaible in for ASP.NET.

You could create two routes, the first being the route that catches your language:

{language}/{page}

The second route would be just

{page}

In MVC we can create route constraints that would enforce the Language to be of a specific value (so like en, en-us, etc) I'm not positive if the same can be done in regular ASP.NET WebForms routing.

Here are two articles that describe the topic of routing in WebForms (non-MVC)

http://msdn.microsoft.com/en-us/magazine/dd347546.aspx

and

http://weblogs.asp.net/scottgu/archive/2009/10/13/url-routing-with-asp-net-4-web-forms-vs-2010-and-net-4-0-series.aspx

EDITED TO ADD CODE SAMPLE

In my Global.asax I registered the following:

 void RegisterRoutes(RouteCollection routes)
 {
 routes.Ignore("{resource}.asxd/{*pathInfo}");
 routes.Add(
 new Route(
 "{locale}/{*url}", //Route Path
 null, //Default Route Values
 new RouteValueDictionary{{"locale", "[a-z]{2}"}}, //constraint to say the locale must be 2 letters. You could also use something like "en-us|en-gn|ru" to specify a full list of languages
 new Utility.Handlers.DefaultRouteHandeler() //Instance of a class to handle the routing
 ));
 }
 void Application_Start(object sender, EventArgs e)
 {
 // Code that runs on application startup
 RegisterRoutes(RouteTable.Routes);
 }

I also created a seperate Class (see asp.net 4.0 web forms routing - default/wildcard route as a guide.)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Compilation;
using System.Web.Routing;
using System.Web.UI;
namespace SampleWeb.Utility.Handlers
{
 public class DefaultRouteHandeler:IRouteHandler
 {
 public IHttpHandler GetHttpHandler(RequestContext requestContext)
 {
 //Url mapping however you want here: 
 string routeURL = requestContext.RouteData.Values["url"] as string ;
 string pageUrl = "~/" + (!String.IsNullOrEmpty(routeURL)? routeURL:""); 
 var page = BuildManager.CreateInstanceFromVirtualPath(pageUrl, typeof(Page))
 as IHttpHandler;
 if (page != null)
 {
 //Set the <form>'s postback url to the route 
 var webForm = page as Page;
 if (webForm != null)
 webForm.Load += delegate
 {
 webForm.Form.Action =
 requestContext.HttpContext.Request.RawUrl;
 };
 }
 return page;
 }
 }
}

This works because when no locale is specified in the URL the default view engine for Web Forms takes over. It also works when a 2 letter locale (en? us? etc) is used. In MVC we can use an IRouteConstraint and do all kinds of checking, like making sure the locale is in a list, checking to see if the path exists, etc but in WebForms the only option for a constraint is using a RouteValueDictonary.

Now, I know there is an issue with the code as-is, default documents don't load. So http://localhost:25436/en/ does not load the default document of default.aspx, but http://localhost:25436/en/default.aspx does work. I'll leave that to you to resolve.

I tested this with sub directories and it works.

• Michael Liu: How do you create a route that maps everything under {language}/{page} to {page}?

Answer 2

You can create an ASP.NET HTTP module that calls HttpContext.RewritePath to map requests from "fr/somepage.aspx" to "somepage.aspx". This technique works best with IIS 7.0 in Integrated mode because relative URLs to scripts and stylesheets will resolve to actual paths like "/fr/jquery.js", and these should be mapped to "/jquery.js" as well.

namespace SampleApp
{
 public class LocalizationModule : IHttpModule
 {
 private HashSet<string> _supportedCultures =
 new HashSet<string>(StringComparer.OrdinalIgnoreCase) { "de", "es", "fr" };
 private string _appPath = HttpRuntime.AppDomainAppVirtualPath;
 public void Dispose()
 {
 }
 public void Init(HttpApplication application)
 {
 application.BeginRequest += this.BeginRequest;
 _appPath = HttpRuntime.AppDomainAppVirtualPath;
 if (!_appPath.EndsWith("/"))
 _appPath += "/";
 }
 private void BeginRequest(object sender, EventArgs e)
 {
 HttpContext context = ((HttpApplication)sender).Context;
 string path = context.Request.Path;
 string cultureName = this.GetCultureFromPath(ref path);
 if (cultureName != null)
 {
 Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo(cultureName);
 context.RewritePath(path);
 }
 }
 private string GetCultureFromPath(ref string path)
 {
 if (path.StartsWith(_appPath, StringComparison.OrdinalIgnoreCase))
 {
 int startIndex = _appPath.Length;
 int index = path.IndexOf('/', startIndex);
 if (index > startIndex)
 {
 string cultureName = path.Substring(startIndex, index - startIndex);
 if (_supportedCultures.Contains(cultureName))
 {
 path = _appPath + path.Substring(index + 1);
 return cultureName;
 }
 }
 }
 return null;
 }
 }
}

Web.config:

<!-- IIS 7.0 Integrated mode -->
<system.webServer>
 <modules>
 <add name="LocalizationModule" type="SampleApp.LocalizationModule, SampleApp" />
 </modules>
</system.webServer>
<!-- Otherwise -->
<system.web>
 <httpModules>
 <add name="LocalizationModule" type="SampleApp.LocalizationModule, SampleApp" />
 </httpModules>
</system.web>

Answer 3

You can update Application_BeginRequest in Global.Asax with this codes. If global.asax does not exists, create it.

Visual Studio Project Virtual Path must be /

protected void Application_BeginRequest(object sender, EventArgs e)
{
 string file_path = Request.RawUrl.ToLower();
 char[] separator = new char[] { '/' };
 string[] parts = file_path.Split(separator, StringSplitOptions.RemoveEmptyEntries);
 if (parts.Length > 0 && parts[0] == "fr")
 {
 System.Threading.Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.CreateSpecificCulture("fr-FR");
 Context.RewritePath("~/" + file_path.Substring(4), true);
 }
 else
 {
 System.Threading.Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.CreateSpecificCulture("en-US");
 }
} 

Answer 4

One option is to put the texts of the aspx within <%$ Resources: My translated text %> tags. Resources tags will be resolved using a ResourceProviderFactory to get the translated value. This ResourceProviderFactory you can create yourself, doing the work of getting the translation from a resource file or database for example (Just implement IResourceProvider.GetObject()). You configure this in the web.config:

<system.web>
 <globalization resourceProviderFactoryType="CustomResourceProviderFactory" uiCulture="fr" culture="en-GB"/>
</system.web>

See: http://msdn.microsoft.com/en-us/library/fw69ke6f(v=vs.80).aspx